SYK and mastitis: Figure 4 shows the results of immunofluorescence colocalization between TLR4 and SYK in bMCEs: the PCC was 0.6277 in control group, and the PCC was 0.8667 (30 min) and 0.8546 (60 min) in bMCEs with LPS, while it was 0.8912 (30 min) and 0.8611 (60 min) in bMCEs with GBS (Supplemental Figure S5). The coimmunoprecipitation analysis also confirmed the direct interaction of TLR4 and SYK in bovine mammary and mastitis tissues (Figure 3B,C).